Iodine deficiency disorder (IDD) is the single most common cause of preventable mental retardation and brain damage in the world. Over one billion people are at risk. Urinary iodide levels are currently the most effective means of determining whether patients have iodide deficiency disorder. There are effective technologies that will prevent iodine deficiency and the problems it causes; however these technologies can be costly and require technical expertise. The objective of this investigation is to develop a simple, rapid, one-step method to determine iodine in aqueous solutions and urine samples, offering third world regions access to and immediate feedback regarding urinary iodide levels. Preliminary results have shown that the proposed one-step test strip will produce acceptable sensitivity and accuracy for a urinary iodine test. PROPOSED COMMERCIAL APPLICATION: Iodine deficiency in the third world regions is well documented. There is also a large population of dieters in the United States that suffer the same problem. The proposed simple to use test strip for urinary iodine will find a very large commercial market.